1. Technical Field of the Invention
The present invention relates to a data transfer equipment for connecting SCSI (Small Computer System Interface) interfaced peripherals with a computer which has an input/output serial bus interfaces such as IEEE 1394 (Institute of Electrical and Electronics Engineers, Inc., Std. 1394-1995 IEEE standard for a high Performance Serial Bus) in an operation system (OS) environment such as Windows for personal computers.
2. Description of the Prior Art
An interface for connecting a personal computer with a digital video cassette recorder (DCR) is disclosed, for example, in JP 10-254811 A (xe2x80x9cControl Method and Equipment for Electronic Appliancesxe2x80x9d).
As shown in FIG. 8, it is disclosed in the above-mentioned document that the control commands for DCR are outputted toward IEEE 1394 communication unit 310 through IEEE 1394 bus 110. Then, system controller 540 converts, through LINK 520, the outputted commands into another kind of commands based on so-called interface device electronics interface (IDE interface) which is a protocol by Western Digital for connecting an IBM/PCAT compatible computer with a hard disk drive (HDD). The commands thus converted is outputted toward IDE controller 710 which outputs data stored in the first-in first-out buffer memory (FIFO memory) 610 through IDE interface 120 toward HDD 400.
However, the conventional data transfer equipment as explained above has a disadvantage that the system becomes large as a whole, because so-called attachment packet interface commands (ATAPI commands) which are completely different from AV/C commands exclusively used for audio visual appliances are required for controlling ADE interfaced appliances, although both ATAPI commands and AV/C commands are defined by IEEE 1394. Concretely, ATAPI commands which are not included in AV/C commands are to be generated.
Therefore, an object of the present invention is to eliminate the topology limitations and termination in a data transfer equipment wherein IEEE 1394 interface and SCSI interface are employed. Further, another object of the present invention is to connect a personal computer with computer peripherals which has SCSI interfaces, by utilizing Hot Plug In/Out function which is one of the features of IEEE 1394 interface.
The data transfer equipment of the present invention which connects a computer having a first interface with peripherals having a second interface, comprises a first connector connected with the computer, a second connector connected with the peripherals, an interface conversion logic unit for exchanging data between the first interface and the second interface, and a cable for connecting the interface conversion logic unit with the first connector.
More concretely, the data transfer equipment of the present invention comprises a physical layer unit for executing the first interface, a link layer unit connected with the physical layer, a management fetch unit for storing packets temporarily, a management agent unit for controlling the packets, a data fetch unit for storing control data included in the packets, and an interface execution unit for executing the second interface. The management fetch unit transfers operation request block (ORB) to the management agent unit, by analyzing packet header. The management agent unit controls the data fetch unit and the interface execution unit, on the basis of ORB. The data fetch unit stores command block in ORB and send the command block to the interface execution unit.
According to the present invention, the topology limitation is mitigated greatly and the termination is not required, because SCSI interfaced peripherals are connected with IEEE 1394 interfaced computer.
Therefore, Hot Plug IN/OUT is available due to IEEE 1394 interface.
Further, according to the present invention, hand-held or mobile computers are easily connected with SCSI interfaced peripherals by metal wire cables.